224 



IRRIGATION. 



of steam in agriculture, and especially in irrigation of 

 arable lands may become usefully available. When we 

 see that the consumption of one bushel of coal, costing 

 20 to 40 cents, in a day, will irrigate 22 acres of land con- 

 tinuously, and as much more than that as the continuity 

 is broken and the consumption per acre is lessened, it 

 becomes very clear that there are many cultivators of the 

 ground that could now make the use of pumps driven by 

 steam to pay them handsomely. 

 Our present mechanical appliances for raising water are 



Fig. 106. METHOD OP OPER- 

 ATING A CENTRIFUGAL PUMP. 



Fig. 105. CENTRIFUGAL PUMP. 



very wonderful. The great rotary pump which discharged 

 the enormous cascade of water at the Cfentennial, which 

 astonished every visitor to that remarkable display of 

 mechanical powers, is able to throw 100,000 gallons per 



